1. Field of the Invention
The present invention relates to an electricity storage module equipped with a cooling means for cooling a plurality of battery cells disposed in an array inside a battery case.
2. Description of Related Art
An electricity storage module known in the related art includes a plurality of battery cells such as a cylindrical lithium-ion secondary batteries housed inside a battery case and connected in series via a bus bar. A power source device for an electric vehicle or a hybrid vehicle is configured with a plurality of such electricity storage modules. Since the battery cells disposed in the battery case at this type of electricity storage module generate heat as they are charged or discharged, a cooling flow passage is formed inside the battery case.
The battery case includes a battery housing portion where batteries, with their axes set parallel to one another are disposed one after another along a direction perpendicular to the axial direction. In the periphery of the battery housing portion, a cooling flow passage, constituted with a cooling space where a cooling medium such as air is allowed to contact the individual battery cells on their outer circumference, is formed. A cooling medium intake-side duct communicating with one end of the battery housing portion and a cooling medium outlet-side duct communicating with another end of the battery housing portion are formed at the battery case.
Japanese Laid Open Patent Publication No. 2003-45504 discloses an electricity storage module with a cooling medium intake-side duct and a cooling medium outlet-side duct formed as integrated parts of the battery case.